Rotary multiple reverse flexing device



July 13, 1965 J. J. BYRNES ROTARY MULTIPLE REVERSE FLEXING DEVICE 2Sheets-Sheet 1 Filed May 16, 1965 IF: GJ.

v INVENT OR Jo/m Joseph Bymes BY 7M July 13, 1965 J. J. BYRNES ROTARYMULTIPLE REVERSE FLEXING DEVICE 2 Sheets-Sheet 2 Filed May 16, 1965INVENTOR JOfi/I ./06,0/2 B/f/MS BY I WM. 1 M m United States Patent3,194,043 ROTARY MULTIPLE REVERSE FLEXENG DEVICE Sohn Joseph Byrnes,Chicago, 113., assignor to Continental Car: Company, Inc., New York,N.Y-, a corporation of New York Filed May 16, 1963, Ser. No. 280,983 13Claims. ((31. 72-163) This invention relates in general to new anduseful improvements in apparatus for use in the manufacture of sheetmetal, and more particularly relates to a novel device to accomplishalternate flexing of continuous tin plate strip and like sheet metal inorder to produce alternate tensile and compressive plastic strains orforces in the metal along a line transverse to the direction of stripmotion to provide an increase in fabrication properties of severely workhardened sheet metal while in creasing the ductility of such strip orsheet metal.

In the manufacture of certain types of sheet metal, particularly thinsteel strip and sheet, the necessary reduction in thickness is obtainedby heavily cold rolling the starting metal stock. The resultant striphas been severely cold worked, frequently by more than 80% reduction,and although very hard and strong, it does not have adequate ductilityfor many uses. For example, if the ultimate product is to be tin platedsteel for the making of can bodies, the hard rolled steel inconventional practice must be annealed and then temper rolled to areduction of about only 1%. This very slight reduction imparts flatnessand also masks the yield point elongation of such steel which otherwisewould be detrimental to can body making or other fabricating processeswhich might be employed, and yet this minor reduction does notnoticeably impair the ductility resulting from the prior anneal.

When such conventional tin plate is desired in thinner gauges, i.e.,less than .008 inch thick, a variety of difficulties are encountered.For example, when thin rolled strips are pulled through an electrolytictinning line, the applied tensile force used to pull the strip sometimesresults in extensive fracture of the strip within the electroplatingline. In order to avoid this difliculty, the steel industry hasintroduced a new type of tin plate to provide the desired thinner gaugesof metal, which new type of plate is produced in such a manner that itis less costly per unit area to produce than heretofore.

The new type of tin plate is produced by additional substantial coldrolling reductions after the metal strip stock has been annealed. Theinitial cold rolling is to a somewhat thicker gauge than normal;followed by annealing, tin plating and a subsequent cold reduction ofthe order of 30% to 60%, resulting in a finished gauge of as low as0.0044 inch, and even lower, if desired. Unfortunately, while thefinished product has a desired thinness and also a desirable highstrength and hardness, these qualities have been obtained by an almostcomplete sacrifice of ductility and by a marked directionality ofproperties. Tensile testing of such material indicates a transverseelongation of the order of 1% or less in a 2 inch gauge length and alongitudinal elongation of from less than 1% to 3%.

In producing such hard and strong but brittle tinplate, it is possibleto electroplate with tin after the second cold reduction to final gaugeand do so without fractures from tension While pulling the strip throughthe electro-tinning line. This may be done because the hard rolled plateis so much stronger than conventional plate and can withstand thetensile forces encountered. An alternative possibility is toelectroplate with a thicker coating of tin prior to the second coldreduction so that upon this 30% to 60% cold rolling the tin coating isre- "ice duced in thickness to the same degree as the steel subtrate. Ineither case, the properties of the steel are essentially identical forequivalent cold reductions so that the problems of utilizing thismaterial are the same.

When cans which have been made from either of these new types of tinplate have the rolling direction parallel to the can axis, severefracturing of the plate is encountered during manufacture. Fractureoccurs primarily during forming of the side seam hook and duringflanging of the can body. These can making operations are ones in whichlarge localized plastic tensile strains are introduced into the metal ina direction transverse to the rolling direction. When these problems areavoided by having the can bodies made with the rolling direction of thetin plate in a circumferential direction, fracture of the cans has beenencountered when, during rough handling, dents were produced in the bodywall below the end seam seal. Therefore, in order to exploit furtherthis newly introduced type of tin plate for can making some of theductility of the metal must be restored. Thermal treatment, such asannealing after the second cold reduction is not practical since thecosts of this operation would make the final product more expensivewhereas the major benefit achieved by its use is the desire for costsavings. Furthermore, if the tin coating were put on prior to the secondcold reduction, this coating will alloy with the steel at the requiredsteel annealing temperatures and thereupon forming an excessive amountof undesired hard and brittle tin-iron alloy.

The present invention is primarily directed to a machine for operatingon this new type of tin plate which has been given a substantial coldreduction before or after tin plating to increase the ductility thereof,or to a presently unavailable but potentially still lower cost platemade without any annealing at all so that it is in the full hard statewith or more cold reduction followed by electroplating with tin.

In the past, metal sheets to be formed into can bodies have beensubjected to a grain breaking process wherein immediately prior to theshaping of the sheets in a can making process, the sheets are passedthrough a grain breaker to assure the formation of a perfectly roundcylinder by preventing the formation of flutes in the can body cylinderas fabricated at high speeds. This grain breaker consists of severalrollers disposed in vertical relation. However, while these rollers haveproduced the desired grain breaking and curvature of the individual canbody blanks, the flexing of the sheets has been relatively light, andthere has been no accompanying increase in ductility of the sheets somechanically treated.

In the steel industry, in order to remove ripples from steel sheets, aswell as other steel shapes, it is common practice to pass the steelthrough leveling rollers. As the steel passes through the levelingrollers, it is ultimately flexed with a resultant flattening of themetal. Such roller levelers used today have only a limited number ofpairs of alternatingly spaced rollers of approximately l1 /2 to 3 inchesin diameter. However, the steel industry does not flex the steel enoughto substantially exceed the yield strength except at initially non-flatportions since the objective is to simply flatten or straighten and notto change any of the physical or mechanical properties of the material.

The present invention proposes broadly to use a machine wherein themetal strip is reversely flexed a large number of times by passing themetal strip between a resilient surface of a large driven drum or rollerand a plurality of small diameter rollers circumferentially spaced aboutthe periphery of the large drum or roller, with the number of completecycles of flexing being in the vicinity of times, thereby requiring onthe order of 100 small diameter a minimum.

.' trate the details of the supporting of the rollers.

machine for reverse flexing a hardened metal strip to inmore severestressing of the metal during eachstressing thereof is obtained, and alarger number of stresses can be produced by a machine of a given size.7

Still another object of this invention is to provide a novel machine foraccomplishing alternate flexing of continuous metal strip wherein thereare many cycles of flexing accomplished on a strip by the machine andwherein themachine is provided with a plurality of small diameterrollers, the rollers being arranged in a circular pattern about theperiphery of a substantially larger drum or roller having a-resilientrubber pad bonded thereto, and the plurality of rollers beingmounted for movement outwardly with respect to the substantially largerdrum'or roller to provide the. necessary clearance for the initialfeeding of an end of the elongated strip through the machine.

A further object of this invention is to provide a novel apparatus foraccomplishing alternate flexing of continu- ,ous metal strip to producealternate tension and compression strains or forces therein, the machinebeing of a compact construction and including a central cylindricalsupport mounting alarge driven drum or roller having a resili entrubberpadded peripheral surface, and a plurality of outer segmental supportseach carrying a set of rollers for cooperation with the. large drum orroller, the outer segmental supports being movable radially with respectto the large drum or roller for the purpose of spacing'the' plurality ofsets of rollers from the large drum'or roller to facilitate the initialfeeding of a strip of metal between the large drum or roller and theplurality of sets of rollers;

'A still further object of this invention is to provide'a novelapparatus for accomplishing the alternate flexing of continuous metalstrip in order to produce alternate tensile and compressive plasticstrains in themetal strip along lines transverse'to the direction ofstrip motion, thedevice including a plurality of sets of rollersdisposed about alarge drum or roller, thelarge drum or roller having arubber padded peripheral surface in yielding contact withithe pluralityof sets of rollers and'defining a sinusoidal path of travel for themetal strip with the path having a generally circular over-all outline,each set of rollers includingsmall diameter rollers for engaging themetal strip and large diameter rollers backing up the small diameterrollers FlGURE 2 is an enlarged fragmentary elevational view of one ofthe plurality of sets of roller support assemblies and the large rubberpadded drum or roller of ,the machine, with portions of the rollersupport assemblies being broken away to more clearly show thearrangement of the rollers and the specific relationship of a metalstrip with respect to the rollers and the substantially larger drum orroller. v l p FIGURE 3 is an enlarged fragmentary generally verti- ..calsectional View taken along line 33' of FIGURE 2, and shows the specificmanner in which the rollers of one of the plurality of sets of rollersis supported;

FIGURE 4 isan enlarged fragmentary horizontal sectional view taken.along line 44 ofFlGURE 2, and shows the relationship of the smalldiameter rollers, the backing up or" thesmall diameter rollers by thelarger diameter rollers, as well as'the specific relationship of themetal strip fwith respect to the small diameter rollers and the rubberinitially rolled, was annealed, after which it was assed throughanelectroplating bath in the customary manner so that tin coatings areapplied to opposite faces thereof. The strip S, after having beencoated, was then passed .through a series of cold reduction rollerswherein the f thickness of the strip S was reduced to 60%. At the end ofthe rolling process, the s trip S is in the form of a new type of hard,cold'rolled tin plate which is now commercially available from a numberof steel mills, e.g.,

whereby the small diameter rollers may be journalledfor lines transverseto the direction'of strip motion, and the.

rollers backing up the small diameter rollers being disposed from theUS; Steel Corporation under the designation Ferrolite? 1 i The 30 to 60%cold rolled plate or,strip,.as it comes from the cold reduction rollersof the steel mill, is relatively hard and brittle, and therefore is onlysuitable for limited field of usage by the can industry. However, it hasa very great economic advantage, where the brittlei ness is relieved bysome operation. For every base box, i.e., 31,360 sq. in.,- which iscoated with tin at a gauge, for example of 0.012 inch, one obtains aftercold rolling a total of two base boxes of tin coated steel 0.006 7 inchthick. The low cost of rolling is such that doubling the area of productis accomplished at a much lower cost than would otherwise be" possible.The steel industry has recognized the lower cost per unit of this hardrolled tin plate orstrip, as compared to'the conventional tin plate orstrip, by pricing it at per base box below that of conventional plate ofthe same gauge. Since the hard rolled plate is much stronger thanconventional plate, one can use a thinner gauge of the hard rolled platewith a further increment of savings of materials cost amounting to 15per box for every reduction in gauge of 0.00055 inch; A potentialsavings to the can industry by the use of the hard rolled plate adds Iup to many millions of dollars. However, the full utilizain'staggeredoverlapping relation whereby each of the small diameter roll ers issupported by a plurality of the large I diameter rollers.

With the above and other objects in View that will hereinafter appear,the nature of the'invention will be more clearly undersood by referenceto the following detailed description, the appended claims and theseveralviews il- FIGURE 1v is anend elevational view of a device 0 y '7machine which is. the subject of this invention and shows the generallayout thereof, portions of the roller supports .tion'of such plate, andobtainment of related savings of metal costs, depends on the improvementin ductility of such hard and brittle plate which may be obtained by theuse or" the apparatus of this invention.

There is another equally or perhaps more important held of applicationof this invention. The hard rolled tin plate or strip referred to thusfar has started as hot I reduction of 80% to 95% results in extremelyhard and strong steel strip which ordinarily is far too brittle to beused in the unannealed state. However, by partially restoring theductility of such material with the practice of this invention, it couldbe employed for many purposes in the hard, unannealed state, either asis or with a subsequently applied tin coating or thin coating of othermetal or material.

The high strength of the extremely hard rolled steel makes possiblefurther reductions in gauge of metal for many fields of utilization,e.g., closures for cans. Not only are there substantial savings inamount of material, but the elimination of annealing and conventionaltemper rolling results in appreciable savings of process cost in theproduction of this hard rolled metal strip. While an appreciable savingsin cost is expected, the exact cost savings is not yet known, because,until the present invention, there has been no way of utilizing suchvery hard and brittle plate and therefore the product has not been madenor priced commercially.

In accordance with this invention, either of these two types of hardrolled plate or strip or any other type of hard, brittle plate or stripmay be further worked upon as part of the continuous forming thereof inthe steel mill, or the plate or strip may be coiled subsequent to thecold reduction operation thereof and later worked upon in accordancewith the invention either at the steel mill or at the can makers plant.For purposes of convenience, the working of the hard and strong butbrittle cold rolled plate or strip S in accordance with the inventionhas been illustrated with the strip S being supplied in coil form.

Referring once again to FIGURE 1 of the drawings, it will be seen thatthe machine 5 includes a suitable base 6 which has a pair of standards 7projecting upwardly from each end thereof. A suitable framework,enerally referred to by the numeral 8, is carried by the standards 7.The framework 8 includes a pair of hubs 9 disposed at opposite ends ofthe machine 5. Each hub 9 has a plurality of arms 10 radiatingtherefrom. It is to be noted that the arms 10 are disposed in equallyspaced relation about the respective hub 9. Two of the arms 10 at eachend of the farmework 8 are secured to the standards 7 at each end of thebase 6. The connection between these certain arms 10 and the standards 7is each referred to by the numeral 11.

The machine 5 includes a large cylindrical drum or roller 12 whichextends between the arms 10 at opposite ends of the framework 8 and isrotatably secured thereto in a manner which will hereinafter be morefully described.

The framework 8 includes an outer support 13 for each of the arms 10 atone end of the framework 8. Extending between every two aligned arms 10at the opposite ends of the framework 8 is one of the outer supports 13.Each of the outer supports 13 carry a roller assembly, generallyreferred to by the reference numeral 14.

At each end of the framework 8 an uppermost one of the supports 10 isprovided with a standard 15. A roller 16 extends between the pair ofstandards 15 and has its ends suitably journalled relative thereto. Theroller 16 is an idler roller and receives the strip S from an uncoilingunit (not shown).

The framework 8 also includes a standard 17 which extends upwardly ateach end thereof from the other of the uppermost ones of the arms 10.The two standards at the two ends of the framework 8 are in alignmentand carry a pair of cooperating drive rollers 18, 19 which are driven ina conventional manner. The strip S, after passing through the machine 5,passes around the drive roller 18 and is delivered to either aconventional roller leveler or a rewind stand (both of which are notshown). The roller 19 cooperates with the roller 18 to feed the strip Sto the machine 5.

The large cylindrical drum or roller 12 has a shaft 20, each end ofwhich is received in an identical bearing 21 mounted in a circularopening 22 in each of the pair of hubs 9 at opposite sides of themachine 5. The shaft 20 of the large cylindrical drum or roller 12 isdriven in a suitable manner by a conventional drive mechanism (notshown) in a counterclockwise direction as viewed in FIG- URE l of thedrawings in cooperative relationship with the drive rollers 18, 19 tofeed the strip S through the machine 5.

The large cylindrical drum or roller 12 is preferably of a hollowconstruction to reduce the weight thereof. The cylindrical constructionof the drum or roller 12 is formed by a pair of identical, spaced,annular plates 23 (only one of which is illustrated) welded or otherwisesecured to the shaft 20 adjacent each of the pair of hubs 9 of themachine 5. A cylindrical member 25 is welded or secured in any otherconventional manner to the peripheries of the annular plates 23 (FIGURE4). A resilient yieldable pad 26, which is preferably constructed fromrubber, is bonded, stretch-fit or otherwise secured to a peripheralsurface 27 of the cylindrical member 25. The large cylindrical drum orroller 12 thus presents a resilient, yieldable pad surface 28 in opposedrelationship to the plurality of sets of rollers 14 mounted about theperipheral surface 27 of the drum 12.

Each of the roller assemblies 14 is formed of a plurality ofcircumferentially spaced identical roller units, each of which isreferred to in general by the reference numeral 29. Each roller unit 29is adjacent and circumferentially spaced about the yieldable pad surface28 of the large drum or roller 12. As is best shown in FIG- URES 2, 3and 4 of the drawings, each of the roller units 29 includes a support,generally referred to by the reference numeral 30. Each support 36includes a base 31 having a plurality of spaced, parallel, arcuatesupport elements 32 projecting inwardly therefrom, the support elements32 extending generally circumferentially around the peripheral surface27 and the yieldable pad surface 28 of the large drum or roller 12.

The support elements 32 receive the ends of short shafts 33, each shortshaft 33 being suported by a pair of adjacent support elements 32. Eachshaft 33 carries a large diameter roller 34 which is disposed between anadjacent pair of the support elements 32. The large diameter rollers 34are mounted in rows extending axially of the large drum or roller 12 asis best illustrated in FIGURE 2 of the drawings, and in overlappingstaggered relation, as is clearly shown in FIGURE 3. No bearing meanshas been illustrated with respect to the shafts 33 and the rollers 34,however, if desired the rollers 34 may be suitably rotatably journalledon the shafts 33 or the shafts 33 may be suitably rotatably journalledin the support elements 32.

The endmost ones of the support elements 32 of each of the supports 30carry an arcuate support 35 (FIG- URES 2 and 3) which is suitablysecured to its respective support element 32 by means of bolts 36, as isbest shown in FIGURE 2. Each of the arcuate supports 35 has a generallyscalloped or sinusoidal inner face 37 defining a plurality of shaftsupporting portions 38. Each shaft supporting portion 38 receives areduced end 39 of a small diameter roller 40. Each small diameter roller40 is rotatably journalled at its ends only but is supportedintermediate these ends by pairs of the large diameter rollers 34.

Each of the supports 13 carries an extensible hydraulic motor 41 whichincludes a shaft 42. The shaft 42, in turn, is secured to a plate 43(see FIGURE 2) which is secured to the base 31 of an associated one ofthe supports 30. In this manner, each of the roller units 29 may bereadily radially adjusted with respect to the resilient rubber pad 26 ofthe large roller or drum 12. One of the primary advantages of theretractability of each of the roller units 29 is the fact that theroller units 29 may be ensgoss sulficienty retracted to permit thefeeding of the initial 7 end of a metal strip, such as the metal stripS,'through the machine 5. However, minor adjustments of the roller units29 may be had for the purpose of compensating for variations in stripthickness.

Particular attention is directed to FIGURE 2, wherein due to theresilient rubber pad 26 f the large drum or mately equal to the increaseof going from ten to one roller 12 and the spacing of the rollers 40,equally about motion as the rubber pad 26 yields and conforms to theconfiguration of the small diameter rollers 43. Furthermore, because ofthe small diameter of the rollers d9 whichrange from inch to inch andpreferably 6.

inch, it will be seen that the strip S will be severely stressed as itis flexed around the rollers 45 7 Particular reference is directed toFIGURE 2, wherein it will be apparent, that as the strip S is flexedaround any two adjacent small diameter rollers 4% of the plurality ofrollers,portions of the metal strip S between any such two' adjacentrollers 40 are flexed around arcuate portion of the resilient rubber pad26 between the rollers 4d. These arcuate portions of the resilientrubber pad 26 are, of course, formed by the force exerted by the smalldiameter rollers 40 against the rubber resilient pad 25 tending to urgeor squeeze portions of the rubber pad 26 between each two adjacentrollers of the plurality of leveling of the strip S. As the hard,coldrolled strip'S passes between the rollers 46 and'theresilient'rubberpad 26 of the large drum or roller :12, it mustbe stressed to the extentthat at least a surface layer of the strip 5 in tension remote from theparticular roller is stressed well beyond the initial yield strength'ofthe metal of the hard rolled strip'S. cold rolled tin plate or striphaving severely coldworl'r steel substrate as the base thereof, thesurface layer of the steel strip under compression is'also stressed wellbeyond the yield strength of'the metal'of the strip S. Tests haveindicated that the metal should be, stressed beyond its yield strengthto a depth of from to 40% of the thickness of the strip S inwardly fromeach stressed facing layer thereof. Of course, the deeperthe penetrationof work within the range specified, the fewer are the number of cyclesof reverse stress required to obtain the desired increase in ductility,but fiexing'rnust obviously be stopped prior to the initiation of anyfatigue damage.

For any given number of cycle for reverse flexing, e .g., 10 or 100 or1,000, there will be a stressbclow the Further, in the working of thehard;

type.

hundred passes." Thus, while in general there was a continuing benefit,the'benefit corresponded .to the loga .rithmic increases in number ofpasses. 'From a commercial standpoint it is. believed that approximately100 complete cycles of reverse flexing is the. most economicallyfeasible number considering results in the way of increase in. ductilityof the strip and the machinery required for obtainingan increasednumberof cycles of reverse fiexure; This would require the engagement of thestrip S width on the order of 100 of each of the rollers 49 as thestripS passes throughthe machine 5. V

The machine 5 isparti cularly adaptable to the required reverse flexingof relatively thin metal strip suchras the strip. S, in thatadequate'support is obtained for the very small diameter rollers tl'sothat a relatively severe flexing of the strip S can be obtained and atthe same time, the machine-5 is extremely compact due to both theprovision of small diameterrollers and the arrangement of the rollers inacircular pattern in lieu of alongitudinal pattern; The particularcircular pattern of the rollers 46 about the larger roller or drum 12permits amachine of reasonable size to accomplish the desired flexing ofa metal strip with the size of the machine being such that it may easilybe placed in a metal strip line of any desired from thelforegoing, itwill be seen that novel and advantageous-provision has been made forcarrying out thedesired end; However, attention is directed to the factthat variations may be made in the example appara: tusfdisclosed hereinwithout departing from the spirit and scope of the invention, as definedin the appended claims.

.Iclaimq I v I '1. A device to accomplish alternate flexing ofcontinuous metal strip in order to produce alternate tension andcompression strains in the strip along lines transverse to the directionof strip motion-to provide an increase in fabrication properties ofseverely work hardened sheet I metal comprising a plurality of, sets ofrollers, first means 7 ers and said means conform to the contourof therollers ultimate tensile strength which will be sufficient to causefracture. The line of stress to cause microcracks versus the number ofcycles to form these at each stress is called a damage curve. It isrequisite, in the practice of this invention, that the number of cyclcsof stressing the surface layers beyond their yield strength by fiexureshould be less than the number of cycles to cause damage at a the stresscaused by that flexure; .Ductility is'increased by this invention whenthe combination of number of carrying a resilient pad.

and is therebysubjected, to alternating tension and com-.

pression strains,-second means for introducing the strip between a firstof said plurality of sets of rollers and said surface, and third meansfor withdrawing the strip from between a second of said'plurality ofsets of rollers and said surface. I

2. The device as defined in claim 1 wherein said first means is a rollerincluding a peripheral surface carrying 'a resilient pad. v Q

. 3..lhe device as defined-in claim 1 wherein said first means isrotatable. I i i a 4. The device as defined in claim 1 wherein saidfirst means is a rotatable roller including a peripheral surface 5. Thedevice as definedinclaim 4 wherein the rotatable roller has a diametersubstantially greater than the diameters of'the rollers of the set ofrollers.

f 6.. A device to accomplish alternate flexing of continuousmetal stripinorder to produce alternate tension and compression strains in thestrip along lines transverse to the direction of strip motion to providean increase in fabrication properties of severely work} hardened sheetmetal comprising a plurality of sets. of rollers, a rotatable drum,said' rotatable drum having a resilient peripheral surface, rollersupport means mounting said plurality ofsets of rollers in adjacentconcentric relationship to said rotatable drum about substantially theentire peripheral surface thereof, and the roller support means havingadjustable mounting means whereby said plurality of sets of rollers maybe moved toward and away from the peripheral surface of the rotatabledrum.

7. A device to accomplish alternate flexing of continuous metal strip inorder to produce alternate tension and compression strains in the stripalong lines transverse to the direction of strip motion to provide anincrease in fabrication properties of severely work hardened sheet metalcomprising, a plurality of sets of rollers, a rotatable drum, saidrotatable drum having a resilient peripheral surface, roller supportmeans mounting said plurality of sets of rollers in adjacent concentricrelationship to said rotatable drum, the plurality of sets of rollershaving a plurality of small diameter rollers and large diameter rollers,and the small diameter rollers being arranged between the rotatable drumand the large diameter rollers whereby deflection of the small diameterrollers is precluded.

8. A device to accomplish alternate flexing of continuous metal strip inorder to produce alternate tension and compression strains in the stripalong lines transverse to the direction of strip motion to provide anincrease in fabrication properties of severely work hardened sheet metalcomprising, a plurality of sets of rollers, a rotatable drum, saidrotatable drum having a resilient peripheral surface, roller supportmeans mounting said plurality of sets of rollers in adjacent concentricrelationship to said rotatable drum, the plurality of sets of rollershaving a plurality of small diameter rollers and large diameter rollers,and the small diameter rollers being arranged between the rotatable drumand the large diameter rollers, said roller support means includingsupport means carrying the large diameter rollers in backing up relationto the small diameter rollers whereby deflection of the small diameterrollers is precluded.

9. The device as defined in claim 8 wherein the diameter of the smalldiameter rollers is between /1 inch and inch.

10. A device to accomplish alternate flexing of continuous metal stripin order to produce alternate tension and compression strains in thestrip along lines transverse to the direction of strip motion to providean increase in fabrication properties of severely work hardened sheetmetal comprising, a plurality of sets of rollers, a rotatable drum, saidrotatable drum having a resilient peripheral surface, roller supportmeans mounting said plurality of sets of rollers in adjacent concentricrelationship to said rotatable drum, the plurality of sets of rollershaving a plurality of small diameter rollers and large diameter rollers,and the small diameter rollers being arranged between the rotatable drumand the large diameter rollers, said roller support means includingsupport means carrying the large diameter rollers in backing up relationto the small diameter rollers whereby deflection of the small diameterrollers is precluded, the large diameter rollers being axially arrangedin transverse rows across the support means with the axes of the largediameter rollers of each row being longitudinally offset from eachother, and the small diameter rollers contacting a plurality of the rowsof the large diameter rollers.

11. A device to accomplish alternate flexing of contlnuous metal stripin order to produce alternate tension and compression strains in thestrip along lines transverse to the direction of strip motion to providean increase in fabrication properties of severely work hardened sheetmetal comprising, a large rotatable drum, said drum including a rubberpadded peripheral surface defining a yieldable arcuate surface, aplurality of sets of rollers circumferentially spaced about the arcuatesurface in a generally circular arrangement, each set of rollersincluding radially adjustable roller support means, a plurality of smalland large diameter rollers carried by said roller support means, thesmall diameter rollers having axis parallel to the rotatable drum axisand arranged in opposing relationship to the yieldable surface of therotatable drum, and the large diameter rollers being arranged inoverlapped rows transversely of the roller support means whereby eachsmall diameter roller is backed up by a plurality of rows of the largediameter rollers.

12;. The device as defined in claim 11 wherein the small diameterrollers and the yieldable arcuate surface define a generally circularsinusoidal path for the continuous metal strip through the device.

13. The device as defined in claim 12 wherein the diameter of the smalldiameter rollers is between A and %1 inch.

References Cited by the Examiner UNITED STATES PATENTS Re. 20,404 6/37Ungerer 153-106 1,715,219 5/29 Biggert 153-54 1,930,562 10/33 Krueger.2,004,596 6/35 Biggert 153106 2,578,820 12/51 Mayer 153-93 3,078,9082/63 MauSt 15386 CHARLES W. LANHAM, Primary Examiner.

1. A DEVICE TO ACCOMPLISH ALTERNATE FLEXING OF CONTINUOUS METAL STRIP INORDER TO PRODUCE ALTERNATE TENSION AND COMPRESSION STRAINS IN THE STRIPALONG LINES TRANSVERSE TO THE DIRECTION OF STRIP MOTION TO PROVIDE ANINCREASE IN FABRICATION PROPERTIES OF SEVERELY WORK HARDENED SHEET METALCOMPRISING A PLURALITY OF SETS OF ROLLERS, FIRST MEANS PRESENTING ARESILIENT ARCUATE SURFACE OPPOSING THE SETS OF ROLLERS, WHEREBY A METALSTRIP TRAVELLING BETWEEN THE ROLLERS AND SAID MEANS CONFORM TO THECONTOUR OF THE ROLLERS AND IS THEREBY SUBJECTED TO ALTERNATING TENSIONAND COMPRESSION STRAINS, SECOND MEANS FOR INTRODUCING THE STRIP BETWEENA FIRST OF SAID PLURALITY OF SETS OF ROLLERS AND SAID SURFACE, AND THIRDMEANS FOR WITHDRAWING THE STRIP FROM BETWEEN A SECOND OF SAID PLURALITYOF SETS OF ROLLERS AND SAID SURFACE.